Скачать или смотреть How to Set Dynamic Border Colors in react-datepicker Based on Validation

Learn how to dynamically change the border color of a react-datepicker input based on validation states like focus, invalid input, and valid date entry using React Hook Form and react-input-mask.
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This video is based on the question https://stackoverflow.com/q/79459430/ asked by the user 'David Gyulinyan' ( https://stackoverflow.com/u/20992470/ ) and on the answer https://stackoverflow.com/a/79469102/ provided by the user 'David Gyulinyan' ( https://stackoverflow.com/u/20992470/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Dynamic Border Color for react-datepicker Inputs Based on Validation

When building forms with date inputs, providing immediate visual feedback helps users understand the input state. In React, using react-datepicker combined with react-input-mask, you can dynamically change the input border color based on validation:

Default state: Neutral border color

On focus (empty input): Purple border

Invalid input (e.g., incomplete date): Red border

Valid input: Green border

This guide shows how to achieve this seamlessly within a controlled React Hook Form Controller.



Setting Up Validation

Leverage React Hook Form's rules.validate method for custom validation:

Ensure the input is not empty.

Check if all date segments are filled (no underscores from the mask).

Parse and verify if the date is valid.

Example validation:

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Dynamically Applying Border Colors

Based on the validation result and input focus, update the input's border color and shadow:

Invalid: Red border and red glow

Valid: Green border and green glow

Focused but empty: Purple border and purple glow

Default: Neutral gray border with no shadow

This can be handled by assigning dynamic classes or inline styles.

Handling Focus and Blur Events

Use onFocus and onBlur handlers on the masked input to update styles immediately:

[[See Video to Reveal this Text or Code Snippet]]

Complete Example

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Additional Tips

Helper Function for Class Names: Consider creating a helper function to determine class names or styles based on the field value and validation.

[[See Video to Reveal this Text or Code Snippet]]

Use CSS classes (.validatedPurple, .validatedGreen, .error) for better maintainability instead of inline styles.

Ensure to trigger re-validation appropriately, especially on blur and change.



This approach improves user experience by giving clear, immediate feedback when entering dates, reducing errors, and making forms friendlier.